Men and women in committed heterosexual relationships are actually pretty good at figuring out whether their partners are happy with their sex lives, according to a new University of Waterloo study (hat tip to io9). Women can gauge their partners' satisfaction better than men (though not significantly), who tended to underestimate their skills. Good sexual communication was key to satisfaction perception, but some couples got away with being stoic types on account of their high "emotion recognition ability." Way to go, couples.